More than half a million people visited forests, nature reserves and national parks yesterday, the first intermediate day of Passover, causing traffic jams on many northern thoroughfares.

Cars crawled along, bumper to bumper, on many roads. The police had to close off southbound traffic on a section of Route 77, as well as redirect some of the northbound cars clogging the road leading to that section.

Two-thirds of the holiday visitors ventured to nature reserves and national parks, while the rest visited Jewish National Fund forests.

"Israelis are littering less this year, or at least cleaning up after themselves," one JNF official said. JNF foresters reported that visitors to most sites collected their waste in bags and deposited it in the bins provided for this purpose at the various sites.

Among the most popular sites were the following: the overhanging pedestrian bridge at the Banias Nature Reserve, which attracted some 5,000 visitors; the horse show at the Caesarea Hippodrome, which drew 4,800 people; dramatized tours at Masada National Park, which 4,200 visited; and the Ein Gedi Nature Reserve on the Dead Sea coast, which saw more than 4,000 visitors.

Many also visited the Gamla nature reserve and Lake Agmon in the Hula Valley, where recycling workshops and a book fair were held. Other visitors frequented the Beit She'an National Park, Carmel National Park, the Judean Hills, the Judean Desert and the Nabatean Market in Mamshit.

The JNF reported many visitors in the Biriya and southern Golan forests.

Parking lots in the Haifa and Mount Carmel area were more than 90 percent full and thousands took to the Carmel beach. Numerous cyclists also rode the trails in Ofer Forest in the southern Carmel.

"Observant Jews joined the many travelers this year, significantly increasing their numbers," said Uzi Barzilai of the INPA.

Forests in the Jerusalem area were also crowded with visitors. At some point, the JNF even redirected people away from Aminadav Forest, which was especially crowded. Many people chose to visit Yatir Forest in the north, while a large event for bike riders was held in Ofakim in the Negev.

Visitors to the Einot Tzukim Nature Reserve adjacent to the Dead Sea can now go on a guided trek into what rangers call the "hidden reserve" - a wilderness area three times larger than the public area, which is not visible from the highway and in the past was closed to outsiders.

A seven-year-old was badly injured and four others lightly to moderately hurt in a three-car crash on Route 65 yesterday. In the southern Golan, an engineering corps force rescued a paratrooper who accidentally landed with a free-fall parachute in an area thought to be a mine field.